Shoe bottom units



4, 6 R. c. MARCY 3,226,851

SHOE BOTTOM UNITS Q Filed Sept. 27, 1963 2 Sheets-Sheet 1 InventorRichard C. Marcy By his A mm Jan. 4, 1966 R. c. MARCY 3,226,851

SHOE BOTTOM UNITS Filed Sept. 27, 1963 2 Sheets-Sheet z United StatesPatent 3,226,851 SHOE BOTTOM UNITS Richard C. Marcy, Marhlehead, Mass.,assignor to United Shoe Machinery Corporation, Boston, Mass, atcorporation of New Jersey i Filed Sept. 27, 1963, Ser. No. 312,210 3Claims. I (Cl. 36-30) This is a continuation-impart of my applicationfor Letters Patent Serial No. 281,931 filed May 21, 1963, now abandoned.

This invention relates to shoes and shoemaking and is length sole andthe heel is the Well known block heel with a square breast face the rearmargin of the sole extends heelwardly for a fraction of an inch beyondthe breast face of the heel and the material comprising the midsole andthe heel flows around the rear margin of the tread sole in the solemolding operation and makes contact with the bottom surface, the topsurface and the edge face of the margin of thesole. Certain solingmaterials, such for example as polyvinyl chloride, do not adhere to mostleathers used in the manufacture of tread soles and consequently therear margin of the tread sole in a shoe of the type above describedincorporating such soling materials is retained in its position in theshoe bottom solely by its physical engagement with the adjacent surfacesof the molded midsole and heel structure. It has been found that in thewear of such a sole and heel unit the normal flexing of the shoe tendsto mispl-ace the rear margin of the tread sole relatively to the forwardor breast portion of the heel thus making desirable some means forsecuring the rear margin of the tread sole to the molded midsole andheel structure.

In order to provide such a securing means the present inventioncontemplates the provision in the rear portion of a tread sole of thetype above described of a plurality of openings or apertures. In themolding operation the fluid soling material flows through the aperturesthus providing a plurality of connectors or legs connecting the breastportion of the heel to the midsole structure and extending through theapertures formed in the tread sole. These legs hold the rear margin ofthe tread sole against any appreciable misplacement relative- 1y to theheel for the life of the sole and heel unit.

Bottom units of the type above described may be molded in situ onto shoebottoms or alternatively they may be separately molded as articles ofmanufacture.

In its application to methods of making sole and heel units either asarticles of manufacture or as units molded in situ onto shoe bottoms thepresent invention contemplates the placement of an appropriately shapedtread sole within a mold :cavity in which sole and heel units are moldedso that the forepa'rt and shank portion of.

the sole is in contact with the bottom of the mold and the rear portionof the sole extends into that portion of the mold cavity in which theheel is formed. The mold cavity is then charged to form a midsole andheel structure. In order to restrict misplacement of the rear portion ofthe tread sole relatively to the heel the rear portion of the tread solehas formed therein apertures through which the moldable material flowsthereby to provide means for attaching the rear portion of the treadsole to the heel.

ice

The invention will now be described with reference to the accompanyingdrawings and pointed out in the appended claims.

In the drawings,

FIG. 1 is a plan view of a sole and heel unit of the type abovedescribed, a section of the breast portion of the heel being broken awayin order to uncover the rear margin of the tread sole;

FIG. 2 is a section taken on the line II-II of FIG. 1; and FIG. 3 is aside elevation of a shoe having molded in situ thereon a sole and heelconstructed as illustrated in FIGS. 1 and 2.

The invention is illustrated in the drawings as embodied in a sole andheel unit generally similar to that disclosed in the Rollman et al.patent above referred to. In the manufacture of such a sole and heelunit a tread sole member, such for example as the three-quarter lengthleather outsole 10 illustrated in FIG. 1, is placed upon the bottom moldmember of a suitable s-ole mold assembly With the rear margin 12 of thetread sole projecting into that portion of the mold cavity in which isformed the heel structure 14. The rear margin of the tread sole,specifically that portion of the tread sole projecting into the heelcavity, is provided with a series of aperture-s, one of which isidentified in FIG. 1 by the numeral 16. With the tread sole 10 held inthe position above described by a peripheral mold member or members themold cavity is charged with a suitable soling material to form a unitarystructure providing a midsole 18 and the heel structure 14. In thecourse of the mold charging operation, fluid soling material flowsthrough the ape-rtures formed in the rear margin 12 of the tread solethus providing a series of legs connecting the midsole structure and theheel structure, one of said legs being identified in FIG. 2 by thenumeral 20.

The midsole and heel structure may be molded from any suitable solingmaterial. A plastomer, such for example as polyvinyl chloride, has beenfound satisfactory as has also vulcanizable rubber. When the midsole andheel structure is molded from polyvinyl chloride the mold charging ispreferably effected by the injection process. A machine suitable forinjecting the midsole and heel structure of a shoe bottom unit of thetype illustrated in FIGS. 1 and 2 is disclosed, for example, in anapplication for United States Letters Patent Serial No. 220,178, filedAugust 29, 1962 in the name of Paul W. Senfleben. The injection moldingof the midsole and heel structure of a shoe bottom unit of the typedescribed, in situ, onto a shoe bottom and onto a prefabricated treadsole placed in the mold cavity can be performed in a machine such, forexample, as that disclosed in United States Letters Patent No.3,006,032, granted October 31, 1961 in the names of Willard L. Baker etal. The performance of this operation in the Baker et al. machinerequires the provision in the prefabricated tread sole of an aperturewhich registers with the sprue bore in the bottom mold member andpermits the fiow of fluid plastic into the space between the tread soleand the shoe bottom.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A shoe provided with a bottom unit comprising a preshaped tread soleand a midsole and heel structure molded to the tread sole and molded insitu onto the shoe bottom characterized by the fact that the midsole andheelstructure encases the rear portion of the tread sole and includes atleast one endless connector extending through a suitable aperture formedin the rear portion of the tread sole, said connector extending betweenthe heel part and the midsole part of said midsole and heel structure.

2. A shoe provided with a sole and heel unit comprising a prefabricatedtread sole and a midsole and heel structure molded in situ to the treadsole and to the shoe bottom characterized by the fact that a rear marginof the tread sole extends into and is encased by the molded heelstructure and has formed therein a series of apertures which are filledwith the heel substance thus providing means restricting misplacement ofthe rear margin of the tread sole relatively to the heel, the heelsubstance extending through the apertures comprising endless legsf-ormed integrally with heel structure and themidsole structure andextending the-re between.

3. As an article of manufacture, a shoe bottom unit comprising apreshaped tread sole and a molded midsole and heel structurecharacterized by the fact that the midsole and heel structure encasesthe rear portion of the tread sole and includes at least one endlessconnector comprising a leg formed integrally with the midsole and heelstructure and extending from the heel part of said structure upwardlythrough an aperture in the tread sole to a junction with the midsolepart of said structure.

References Cited by the Examiner UNITED STATES PATENTS 58,623 10/1866Elliott 3630 2,826,832 3/1958 Rollman et al, 36--28 3,116,566 1/1964Ferreira 3630 FOREIGN PATENTS 1,016,468 8/1952 France.

JORDAN FRANKLIN, Primary Examiner.

1. A SHOE PROVIDED WITH A BOTTOM UNIT COMPRISING A PRESHAPED TREAD SOLEAND A MIDSOLE AND HEEL STRUCTURE MOLDED TO THE TREAD SOLE AND MOLDED INSITU ONTO THE SHOE BOTTOM CHARACTERIZED BY THE FACT THAT THE MIDSOLE ANDHEEL STRUCTURE ENCASES THE REAR PORTION OF THE TREAD SOLE AND INCLUDESAT LEAST ONE ENDLESS CONNECTOR EXTENDING THROUGH A SUITABLE APERTUREFORMED IN THE REAR PORTION